DEBUG: cli: add a new "debug dev deadlock" expert command
This command will create the requested number of tasks competing on a
lock, resulting in triggering the watchdog and crashing the process.
This will help stress the watchdog and inspect the lock debugging parts.
diff --git a/src/debug.c b/src/debug.c
index 45e91e0..639f937 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -457,6 +457,36 @@
return 1;
}
+/* this is meant to cause a deadlock when more than one task is running it or when run twice */
+static struct task *debug_run_cli_deadlock(struct task *task, void *ctx, unsigned int state)
+{
+ static HA_SPINLOCK_T lock __maybe_unused;
+
+ HA_SPIN_LOCK(OTHER_LOCK, &lock);
+ return NULL;
+}
+
+/* parse a "debug dev deadlock" command. It always returns 1. */
+static int debug_parse_cli_deadlock(char **args, char *payload, struct appctx *appctx, void *private)
+{
+ int tasks;
+
+ if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
+ return 1;
+
+ _HA_ATOMIC_INC(&debug_commands_issued);
+ for (tasks = atoi(args[3]); tasks > 0; tasks--) {
+ struct task *t = task_new_on(tasks % global.nbthread);
+ if (!t)
+ continue;
+ t->process = debug_run_cli_deadlock;
+ t->context = NULL;
+ task_wakeup(t, TASK_WOKEN_INIT);
+ }
+
+ return 1;
+}
+
/* parse a "debug dev delay" command. It always returns 1. */
static int debug_parse_cli_delay(char **args, char *payload, struct appctx *appctx, void *private)
{
@@ -1535,6 +1565,7 @@
{{ "debug", "dev", "bug", NULL }, "debug dev bug : call BUG_ON() and crash", debug_parse_cli_bug, NULL, NULL, NULL, ACCESS_EXPERT },
{{ "debug", "dev", "check", NULL }, "debug dev check : call CHECK_IF() and possibly crash", debug_parse_cli_check, NULL, NULL, NULL, ACCESS_EXPERT },
{{ "debug", "dev", "close", NULL }, "debug dev close <fd> : close this file descriptor", debug_parse_cli_close, NULL, NULL, NULL, ACCESS_EXPERT },
+ {{ "debug", "dev", "deadlock", NULL }, "debug dev deadlock [nbtask] : deadlock between this number of tasks", debug_parse_cli_deadlock, NULL, NULL, NULL, ACCESS_EXPERT },
{{ "debug", "dev", "delay", NULL }, "debug dev delay [ms] : sleep this long", debug_parse_cli_delay, NULL, NULL, NULL, ACCESS_EXPERT },
#if defined(DEBUG_DEV)
{{ "debug", "dev", "exec", NULL }, "debug dev exec [cmd] ... : show this command's output", debug_parse_cli_exec, NULL, NULL, NULL, ACCESS_EXPERT },